： +8618979570760 ：xuran1603@gmail.com WhatsApp：+8619170756831
English
 |
| Quantity: | |
|---|---|
SW Flange
SDFL
The F304 PN16 RF socket weld flange is a forged hubbed flange for small-bore steel piping. The pipe is inserted into the socket, aligned with a specified expansion gap, and secured with a fillet weld at the socket end. The RF face supports a gasket between mating flanges.
Precision socket bore ensures accurate pipe alignment and consistent weld quality
1.6 mm expansion gap reserved to prevent thermal stress cracking after welding
Single-side fillet weld design simplifies on-site installation for small-bore piping
This flange is intended for industrial water, circulating cooling water, compressed air, and general utility piping where the project specification calls for PN16, RF, socket weld construction. It is not a universal pressure rating: design pressure, temperature, gasket selection, bolting, and pipe schedule must be confirmed against the applicable standard and project design.
The default material is ASTM A182 Grade F304 austenitic stainless steel. For current PN-designated Chinese steel pipe flanges, the applicable reference is GB/T 9124.1-2019. GB/T 9117-2010 may be referenced for legacy projects. F304 is suited to general water and utility service; corrosive or chloride-rich applications require engineering review. Material test reports, PMI, dimensional inspection, visual inspection, and third-party inspection can be arranged before dispatch.
Item | Details |
|---|---|
FLANGE TYPE | Standard: Socket Weld (SW) Flange;other flange types available upon request |
SIZE RANGE | Standard: DN10 – DN50 (GB/T 9124.1 PN16); Custom sizes available per customer drawing |
PRESSURE RATING | Class 150 – 2500, PN0.6 – PN400, 5K – 40K |
SEALING FACE | RF, FF, RTJ, Tongue & Groove, customizable |
STANDARDS | ASME B16.5, EN 1092-1, DIN, JIS B2220, GOST 12821, GB/T 9124.1-2019, custom standards |
MATCHED PIPE SCHEDULE | SCH5S – SCH160 |
MATERIAL | Standard: ASTM A182 F304 / F304L Optional: F304/F304L, F316/F316L, F321, F347, duplex steel, nickel alloys, carbon steel |
SURFACE TREATMENT | Pickling & Passivation, As-machined, Mechanical Polishing, Electropolishing (EP) |
Applications | Petrochemical, pharmaceutical, power plants, shipbuilding, water treatment, general industrial piping |
Units: millimetres, except DN and bolt quantity.
Nom. Pipe Size | O | T | R | X | No./Dia. of Holes | Bolt Circle Dia | L2 | H | B2 | L | B | r | L3 | B3 | D | C | Thr |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
1/2 | 3.75 | 0.56 | 1.38 | 1.5 | 4-0.62 | 2.62 | 2.06 | 0.84 | 0.62 | 0.88 | 0.88 | 0.12 | 0.88 | 0.90 | 0.38 | 0.93 | 0.62 |
3/4 | 4.62 | 0.62 | 1.69 | 1.88 | 4-0.75 | 3.25 | 2.25 | 1.05 | 0.82 | 1.00 | 1.09 | 0.12 | 1.00 | 1.11 | 0.44 | 1.14 | 0.62 |
1 | 4.88 | 0.69 | 2.00 | 2.12 | 4-0.75 | 3.50 | 2.44 | 1.32 | 1.05 | 1.06 | 1.36 | 0.12 | 1.06 | 1.38 | 0.50 | 1.41 | 0.69 |
1-1/4 | 5.25 | 0.75 | 2.50 | 2.50 | 4-0.75 | 3.88 | 2.56 | 1.66 | 1.38 | 1.06 | 1.70 | 0.19 | 1.06 | 1.72 | 0.56 | 1.75 | 0.81 |
1-1/2 | 6.12 | 0.81 | 2.88 | 2.75 | 4-0.88 | 4.50 | 2.69 | 1.90 | 1.61 | 1.19 | 1.95 | 0.25 | 1.19 | 1.97 | 0.62 | 1.99 | 0.88 |
2 | 6.50 | 0.88 | 3.62 | 3.31 | 8-0.75 | 5.00 | 2.75 | 2.38 | 2.07 | 1.31 | 2.44 | 0.31 | 1.31 | 2.46 | 0.69 | 2.50 | 1.12 |
2-1/2 | 7.50 | 1.00 | 4.12 | 3.94 | 8-0.88 | 5.88 | 3.00 | 2.88 | 2.47 | 1.50 | 2.94 | 0.31 | 1.50 | 2.97 | 0.75 | 3.00 | 1.25 |
3 | 8.25 | 1.12 | 5.00 | 4.62 | 8-0.88 | 6.62 | 3.12 | 3.50 | 3.07 | 1.69 | 3.57 | 0.38 | 1.69 | 3.60 | 0.81 | 3.63 | 1.25 |
3-1/2 | 9.00 | 1.19 | 5.50 | 5.25 | 8-0.88 | 7.25 | 3.19 | 4.00 | 3.55 | 1.75 | 4.07 | 0.38 | 1.75 | 4.10 | / | 4.13 | 1.44 |
4 | 10.00 | 1.25 | 6.19 | 5.75 | 8-0.88 | 7.88 | 3.38 | 4.50 | 4.03 | 1.88 | 4.57 | 0.44 | 1.88 | 4.60 | / | 4.63 | 1.44 |
5 | 11.00 | 1.38 | 7.31 | 7.00 | 8-0.88 | 9.25 | 3.88 | 5.56 | 5.05 | 2.00 | 5.66 | 0.44 | 2.00 | 5.69 | / | 5.69 | 1.69 |
6 | 12.50 | 1.44 | 8.50 | 8.12 | 12-0.88 | 10.62 | 3.88 | 6.63 | 6.07 | 2.06 | 6.72 | 0.50 | 2.06 | 6.75 | / | 6.75 | 1.81 |
8 | 15.00 | 1.62 | 10.62 | 10.25 | 12-1.00 | 13.00 | 4.38 | 8.63 | 7.98 | 2.44 | 8.72 | 0.50 | 2.44 | 8.75 | / | 8.75 | 2.00 |
10 | 17.50 | 1.88 | 12.75 | 12.62 | 16-1.12 | 15.25 | 4.62 | 10.75 | 10.02 | 2.62 | 10.88 | 0.50 | 3.75 | 10.92 | / | 10.88 | 2.19 |
12 | 20.50 | 2.00 | 15.00 | 14.75 | 16-1.25 | 17.75 | 5.12 | 12.75 | 12.00 | 2.88 | 12.88 | 0.50 | 4.00 | 12.92 | / | 12.94 | 2.38 |
14 | 23.00 | 2.12 | 16.25 | 16.75 | 20-1.25 | 20.25 | 5.62 | 14.00 | 13.25 | 3.00 | 14.14 | 0.50 | 4.38 | 14.18 | / | 14.19 | 2.50 |
16 | 25.50 | 2.25 | 18.50 | 19.00 | 20-1.38 | 22.50 | 5.75 | 16.00 | 15.25 | 3.25 | 16.16 | 0.50 | 4.75 | 16.19 | / | 16.19 | 2.69 |
18 | 28.00 | 2.38 | 21.00 | 21.00 | 24-1.38 | 24.75 | 6.25 | 18.00 | 17.25 | 3.50 | 18.18 | 0.51 | 5.12 | 18.20 | / | 18.19 | 2.75 |
20 | 30.50 | 2.50 | 23.00 | 23.12 | 24-1.38 | 27.00 | 6.38 | 20.00 | 19.25 | 3.75 | 20.20 | 0.55 | 5.50 | 20.25 | / | 20.19 | 2.88 |
22 | 33.00 | 2.63 | 25.25 | 25.25 | 24-1.63 | 29.25 | 6.50 | 22.00 | 21.25 | 4.00 | 22.22 | 0.50 | 5.75 | 22.25 | / | 22.19 | 3.13 |
24 | 36.00 | 2.75 | 27.25 | 27.62 | 24-1.62 | 32.00 | 6.62 | 24.00 | 23.25 | 4.19 | 24.25 | 0.50 | 6.00 | 24.25 | / | 24.19 | 3.25 |
Each flange can be marked with material grade, pressure designation, nominal size, standard, manufacturer mark, and heat or lot identifier. Marking should match the supplied material documents.
Before welding, verify the pipe outside diameter, socket bore, flange face, and weld end condition. Remove contamination from the socket and pipe. Maintain a 1.6 mm (1/16 inch) expansion gap. Welding should follow an approved WPS and be performed by qualified welding personnel.
Use gaskets and bolting of the specified size and material. Tighten bolts using a controlled sequence and torque values approved for the service. After installation, inspect the face, weld, alignment, and test records. Available documents may include material certificates, dimensional records, inspection reports, and packing lists.
1. Raw Material PMI Spectral Inspection
2. Closed-die Hot Forging (Hydraulic Forming Press)
3. Solution Heat Treatment (Continuous Heat Treatment Line)
4. Precision CNC Machining (5-axis Machining Center, High-precision CNC Lathe)
5. Semi-finishing Dimensional & Surface Inspection
6. Surface Finishing (Pickling & Passivation / Mechanical / Electropolishing)
7. Final Quality Control (Dimensional Test, NDT, Surface Defect Check)
8. Export Standard Packaging
9. Delivery
To prepare a quotation, please provide DN, pipe series and outside diameter, standard, pressure designation, face type, material, quantity, required certificates, and delivery location. Provide drawings for nonstandard dimensions or special inspection. The standard GB PN16 range is DN10-DN50; sizes outside that range require engineering review and should not be represented as standard GB PN16 socket weld flanges.
Material Verification: 100% PMI spectral analysis, chemical composition fully traceable to original mill melt number
Dimensional Control: High-precision dimension inspection, strict tolerance compliance with international standards
Non-destructive Testing: Penetrant test, ultrasonic test, radiographic test available on request
Surface & Cleanliness: Surface defect inspection; sanitary grade electrolytic polishing & cleanliness test
Third-party Inspection: SGS, BV, TUV witnessed inspection supported
16+ Years Professional Manufacturer (Founded in 2010, based in Wenzhou, China)
Full In-house Production Chain: Forging → Heat Treatment → CNC Machining → Testing
Leading Special Alloy Technology: Mature processing of nickel-based, Hastelloy, super austenitic and super duplex steel
Dual Product System: Industrial heavy-duty flanges + Sanitary high-purity flanges
Complete Authoritative Certifications: TS pressure pipe license, ISO 9001/14001/45001, CE-PED, AD2000, EAC
Full Engineering Support: Working condition analysis, material selection, custom solution design
New Energy Layout: Professional piping solutions for data center liquid cooling, hydrogen energy and energy storage
Stable & Reliable Delivery: exported to 30+ countries
 |  |  |
 |  |  |
 |  |  |
It is used to connect small-bore pipe in utility, water, compressed air, and other specified industrial systems. The socket positions the pipe before a fillet weld is applied.
For current PN-designated Chinese steel pipe flanges, use GB/T 9124.1-2019. GB/T 9117-2010 is a superseded standard and may be used only as a legacy reference.
The PN16 hubbed socket weld table covers DN10 through DN50. DN15, DN20, DN25, DN32, DN40, and DN50 are included in that range.
The default material is ASTM A182 F304 stainless steel. Other grades require separate selection.
A flange alone does not establish a pressure-tested joint. Pressure testing normally applies to the installed piping assembly. Component inspection or third-party verification can be arranged before shipment.
Send the size, pipe outside diameter, standard, PN rating, face type, material, quantity, certification requirements, and delivery address. For custom items, include drawings and service conditions.
Socket weld flanges use an internal socket for pipe insertion with a single fillet weld, offering higher strength and better alignment for small-bore pressure lines. Slip on flanges slide over the pipe and require welding on both sides, more cost-effective for larger low-pressure piping.
Standard PN16 socket weld flanges are compatible with SCH40 and SCH80 steel pipes; custom socket bores for other wall thicknesses can be produced per your requirements.
